Tag Archives: salamander

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This morning I went into the lab at 8:00 am to clean the cages of all 90 salamanders, as is my habit on Fridays, but when I got to number 80, a ledback juvenile, I noticed that he had developed a growth on his torso, and, even more worrisome, he seemed rather listless. I decided to clean his cage and put it aside until I could address the problem with my thesis advisor.

After my 9:30 am class, I emailed my thesis advisor to let him know about my concerns. I asked him to take a look at the youngster and, surely enough, at 4:00pm today, the little guy was pronounced dead.

I’m a bit sad about losing one my salamanders, especially since it was a juvenile and should have had at least another 6 years of life ahead of it. My advisor did not identify a cause of death, but it is possible that it was sick. I must now be extra vigilant when handling the other salamanders. I will monitor them more closely to make sure that they don’t develop similar symptoms. I truly hope that I will get to release 89 beautiful amphibians next April.

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We are now halfway through the Fall semester. The inevitably of midterms being unleashed onto the undergraduate population can no longer be ignored. If you are anything like me, you are probably feeling nostalgic about the peaceful library you had the privilege of enjoying all by your lonesome in the first weeks of September, where finding a quiet seat near a plug for your computer did not mean having to plan an overnight stake-out or resorting to bribery  (“Baked goods for anyone who will give up their study cubicle!”).

Yep. The fall semester is in full swing. The leaves are turning burnt orange and cherry red. Unusually clean, dolled-up students are having their grad photos taken all over campus, all while pretending that they aren’t freezing in classic academic dress and stockings. Science graduate TAs are slowly but surely turning into lab zombies smeared in red ink from falling asleep while grading papers and running assays simultaneously.

In others words, these last couple of weeks have been business as usual and I am no exception. I’ve been writing midterms and lab reports, covering science news, and running my experiment to the best of my abilities. The salamanders seem to be reacting to both the chemical and visual cues alone, but until I compile my results, this will be hard to evaluate. I am almost halfway done with the first experiment and as soon as my midterms are over, I will start copying my data into an Excel file to see if any trends are developing. Stay tuned!

Science News Links

1. This week’s Scientifically Inclined column addressed a subject most of us have pondered but were probably too shy to ask about: The reason behind the bumps on women’s nipples. Read my article to find out more.

2. Scientists at Georgia Tech have managed to turn the iphone into a device that can figure out what words you are typing on your computer’s keyboard. This new form of spyware works by detecting the vibrations caused by stroking pairs of keys when it is placed on a table next to a computer. The iphone uses probabilities to infer the words being typed and has an 80% accuracy rate. Add a little context to the equation and anyone equipped with this device could easily figure out the secret ingredient to your world-famous pound cake or, worse yet, the password to your email and banking accounts.

3. Encouraging students to work hard in school in order to get a well-paying job is killing their motivation. A new study has found that materialistic students or students who are encouraged to pursue higher education as a means of avoiding the repercussions of the current economic crisis are far less prone to work hard and to be successful in school. Want your kids to do their best? Encourage them to do what they love instead of what will allow them to pay for what they love.

4.   Why would a male millipede “sing” when its entire species can’t hear? This study hypothesizes that the millipede’s stridulations, caused by the male’s segments rubbing together, are used to convince females to uncoil when they are in defensive positions. I’ll let good old Mark “Marky Mark” Walhberg explain how these hearing-impaired females manage to perceive a male’s song.

Science Video of the Week

I got great feedback from the video I posted last week so I will do my best to incorporate a science video into this blog post every week. This highly recommended video beautifully addresses the mystery that is our inability to walk in a straight line when our vision is obstructed. Enjoy!

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The experiment has begun, and so the time has come to explain what it is exactly that I am attempting to accomplish over the course of the next two semesters. I have already stated my three hypotheses in a previous blog post, but here they are again… just in case they’ve slipped your mind!

Hypothesis 1: I Hypothesize that the visual modality is involved in conspecific interactions between pairs of red-backed salamanders and that it interacts with the olfactory modality.

Hypothesis 2: I hypothesize that olfactory cues or the visual cues contain information about the sexual identity of the competitor.

Hypothesis 3: I hypothesize that colour vision plays a role in salamander conspecific interactions.

Experiment 1

In order to support or disprove my hypotheses, I have come up with three experiments. This week, I started the first experiment, which addresses my first hypothesis. It is a cue isolation experiment, in which 40 salamanders (20 mature males and 20 juveniles) will undergo 4 separate treatments:

Treatment 1 (OV): In this treatment the salamander will be confronted with a male olfactory cue (O), in the form of the moist paper towel lining the cage of another male salamander,  and a male visual cue (V) in the form of a video I made of a male salamander.

Treatment 2 (OC):This treatment will subject the salamander to the moist paper towel of another male salamander and a control visual cue (c). The control visual cue is a video depicting the same background present in the other visual cue, only this time there will be no salamander in the clip.

The experimental setup. As you can see, there is a computer screen that playing the video clip. I use two empty cages to contain the salamander within the testing area, but it can still escape if it really wants to. Half the testing area is covered by the salamander's own paper towel and the other half is covered by either a control paper towel or another male's paper towel. I work in the dark under a red-illumination.

Treatment 3 (CV): This treatment is made of a control olfactory cue (C) consisting of a moist paper towel that will have spent 5 days in a salamander cage devoid of a salamander. The visual cue is a video of a salamander this time.

Treatment 4 (CC): This is the complete control treatment. Both the visual and the olfactory cues are controls; this treatment has no salamander smell or image in it.

As the “cue isolation” name suggest, I will attempt to isolate the treatment that solicits the strongest behavioural response in the salamanders. For obvious reasons, I expect the OV treatment to elicit the strongest response. I am also very interested in finding out how the OC and CV treatments compare to a treatment where both sensory modalities (OV) are stimulated.

Each treatment will last 15 minutes unless the salamander escapes the testing area. This is not necessarily a bad thing, mind you, as I am also recording “latency to escape”, meaning how long it takes for the salamander to escape. This information could be valuable because this demonstrates a certain level of distress. One could predict, for instance, that salamanders undergoing the OC, CV and OV treatments will be much more likely to escape then the ones undergoing the CC. As you can imagine, I have to be very vigilant when running this experiment – I don’t want to lose any of my little guys!

How does a salamander behave anyways?

The red-backed salamander is territorial. This means that it does not take kindly to intruders. A face-off between two salamanders will usually determine which one is  dominant and which is submissive. A salamander that looks directly at an intruding salamander or that lifts its trunk off the ground when confronted with an intruder, often arching its back like a cat, is displaying dominant behaviours meant to intimidate. These behaviours can sometimes lead to biting although they never bite to kill.

On the other hand, a salamander that looks away from an intruder or that lays its entire body, including its head, flat against the substrate is being submissive and might very well lose its highly prized territory. Finally, behaviours like running away, climbing the walls or hiding underneath the substrate are all called “escape” behaviours and, once again, these do not bode well as to the salamander’s chances of maintaining its territory.

During each treatment, I will record the behaviours I observe, their length as well as their location. A statistical analysis will help me interpret the data I collect and determine if there is a significant difference in behaviour between each treatment.

Thinking ahead

In the grand scheme of things, this is a rather simple experiment. I can’t imagine what minutiae chemists, bacteriologists or physicists have to demonstrate when planning and performing the experiments that make them great. One must analyze every little aspect and anticipate any problems one might encounter. For instance, previous studies have shown that it takes five days for the salamanders to establish a territory by laying down chemical cues onto the substrate at the bottom of their cages. That means that I can only perform my experiment three nights a week, given that I feed the salamanders on Thursdays and that I clean their cages and replace their paper towels on Fridays.  I have to wait until Tuesday to experiment with proper male olfactory cues because otherwise my cues won’t be valid. I can run certain trials, the ones that use control olfactory cues, on Mondays however. This will allow me to complete experiment 1 and 2 before the end of the semester.

Truly, it is of the utmost importance that I stay on top of things so that everything goes smoothly. Despite having realized that I do not want to pursue zoology as a career anymore, I am as emotionally invested in this experiment as ever. It is my belief that this experiment is worth doing well. With a little bit of luck and some careful planning, I might just make a decent contribution to neurobiology and the science of animal behaviour. Here’s hoping!

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I really enjoy caring for the salamanders first thing in the morning. Instead of going straight to class or to the gym, I get to hang out with animals that fascinate me while I wake up to the world around me. I guess I’ve always enjoyed being alone in the morning. When I worked at the Montreal Bakery “Au Pain Doré”, I systematically volunteered to go down to the basement and do the morning baking at 6:30 a.m. It was a time for me to relax and reflect on my life and my most recent experiences before confronting our caffeine-and-sugar deficient customers.

Caring for salamanders is much more fulfilling. Observing animals that are so very different from myself is quite the experience. I have come to anticipate their behaviours, whether it be fright, curiosity, or hunger for that matter. I now appreciate the subtleties of their reactions to my care. Through my research, I can tell when a salamander is being submissive or dominant. Through routine care, I can tell when a salamander will strike to catch a tasty cricket. I feel lucky that I can witness and recognize these behaviours. I am careful to avoid the term “understand” however, because that would be wildly presumptuous of me.

Twice a week, for the first two hours of my day, all I have to think about are those salamanders and their needs. Needs that aren’t anywhere near those of over privileged Canadian university students such as myself.  Basic needs – the kind that keep you alive, fit, and ready reproduce so you can pass on your genes to the next generation. Morning salamander care is a time for me to visit the characteristics that unite us to all living things instead of what separates us from them. Too often I find that the media try to convince us that we are superior to beings the likes of amphibians or insects. That couldn’t be farther from the truth. Just like us, they have evolved in ways that ensure their survival in their own habitats. I wouldn’t survive in the ground or under a rock – but these little guys can.

I’m still learning. For the first time, I am handling juvenile salamanders. They range from 1 to 2 years of age and are about half the size of their mature counterparts.

A Red-backed salamander hatchling. The one-year-olds are a tad bigger than this one. Picture by Daniel Hocking.

If I was afraid of accidentally losing an adult over the summer, I am now absolutely terrified at the idea of losing sight of one of the “kids”.They are just as fast as the adults and probably twice as jumpy. Thus, I vow to be four times as vigilant, just for good measure.

Last night, I attended my second thesis course meeting, in which students enrolled in the course made a 5-minute presentation about their thesis topic. I had imagined that by the 25th presenter my attention would wane, but instead I found myself just as excited and engaged as I did when the first project was revealed. Their chosen areas of study were generally interesting but it was the passionate cases they made addressing the relevance of the science that won me over. Have you ever noticed how contagious passion can be? Moss does not electrify me. I enjoy its presence for its cushioning properties when in need of a break on a hike, but otherwise, I rarely stop to ponder its contribution to my environment. That being said, when the young woman who will spend two semesters studying this primary producer made her case, I was enthralled.

Moss was not the only interesting subject of course. Sharks, tarantulas, ants, parasites, falcons and monarch butterflies will all be observed and examined by my fellow undergrads.

I was also incredibly impressed by the innovative ideas that were being presented. Granted, all the students in the course are closely advised by a faculty member and most of them did not come up with their research ideas on their own, but I must say that, having been through the brain-storming process myself, I know that many of them put their heart and soul into the conception of these experiments. Whereas, I had entered the room with, I admit, a slightly competitive demeanor, I left it cheering my classmates on and wishing them luck.

As for my own presentation – it was, I believe, a success. I managed to explain the questions I am trying to answer and, equally important, I made people laugh. I don’t believe my experiment is the most interesting or the most complicated, but I’d like to believe that that was not the point of the exercise. Last night, I witnessed curiosity, bewilderment and the subsequent enchantment that can arise from both. For three hours, we weren’t 20-somethings trying to prove ourselves as scientists but children exhilarated by our own invention and imagination.

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Fall is in the air and so are the germs that usually come along with it. My body is a temple that has come under siege by a nasty cold this weekend, and it seems to be impairing my reasoning and analytical skills somewhat – let’s hope I don’t subject you to reading anything too foolish.

Despite having a sore throat, a headache and a stuffy nose, I braved the cold air this morning to go out into the “wilderness” that is Rockwood Park in order to find some more red-backed critters. My thesis advisor and I were a bit worried about this expedition given the cool 17°C that was predicted for the day. There was a chance that we wouldn’t be able to collect any salamanders because they would have borrowed deep into the soil to keep warm. The scientifically inclined gods were with us, however, and we managed to trap 83 salamanders.

I was very happy to see families and couples in the Park. Unlike our skin-breathing friends, the cold didn’t seem to detract them from showing up and enjoying the sights. I got to chat with a lovely couple that wanted to know what I was up to as I feverishly (possibly literally) flipped rocks over. When I told them I was looking for salamanders, they didn’t seem to find it odd that I was capturing wild animals in a protected Park. I explained to them that I was an undergrad collecting specimens for her research and I guess that was enough for them. On both salamander catching expeditions, people stopped to ask me what I was doing but no one ever asked me whether I had a permit. I must look extremely trustworthy.

Back in the lab, I sexed all of the freshly-caught salamanders.  We ended up meeting our goal of having 60 testable males, 20 juveniles and 10 females. The remaining salamanders will be released in the next couple of days. In two weeks, the salamanders we have kept will have acclimated to the lab and I will be able to begin my experiments.

The time seems ripe now to tell you a bit more about my research topic and the questions I hope to answer over the course of two semesters. My thesis, Sensory determinants of conspecific interactions in the red-backed salamander (Plethodon cinereus), will address three questions in three separate experiments:

1. Is the visual modality involved in conspecific (meaning of the same species) interactions between pairs of red-backed salamanders?

2. Do odours or the visual cue contain information about the sexual identity of the competitor?

 3. Does colour vision play a role in salamander conspecific interactions?

Previous studies have already determined the importance of olfactory cues in the interactions of the red-backed salamander (McGavin, 1978; Jaeger 2007) but the role of vision has not yet been determined. We do know, however, that nocturnal vision plays a role in general amphibian social behaviours (Buchanan, 1998; Gomez et al., 2009).

Why is this relevant? Well, this research project will, hopefully, help shed some light on how information from different sensory modalities is integrated to guide social behaviour, further advancing our knowledge of sensory integration mechanisms.

On tuesday, I must present these questions as well as the methods I will use to both the thesis course coordinator as well as 30 other students enrolled in the thesis course. We must prepare a 5-minute powerpoint presentation as well as a one-page outline of the work we hope to accomplish over the course of the year. This is all being done in preparation for the full research proposal that we must hand in at the beginning of October.

I am really looking forward to hearing what the other students will be researching. It’s always fascinating to me to hear scientists (or in this case, budding scientists) explain their thought processes and reveal their innovative new ideas. I will give you my impressions of the next thesis course meeting in the coming days.

As for the details of my experiments, you will simply have to keep visiting my blog!

Cheers.

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The Art of Catching Salamanders in Ten Steps

A new school year has begun. The calm, empty campus that I had grown accustomed to over the summer while working in the herpetology lab is now infested with eager as well as not-so-eager young minds. I feel rather strange when I think about this being my last year of undergraduate studies. I will miss the beautiful scenery and the lovely atmosphere cultivated by the dozens of wonderful people that I have befriended in this town. That being said, I am also terribly excited about the idea of discovering a new city and campus. Already, I can feel my blood thicken with the urge to explore and relocate.

Classes started on Thursday and I am happy to report that not only am I genuinely interested in the content of all the courses I am taking this semester, but my professors also all seem to enjoy teaching and interacting with students. This is an auspicious start to the fall semester.

On Saturday morning, I met my thesis advisor at the lab so we could prepare for a day of salamander collecting. The plan was to release the 110 salamanders that we had caught in early May as well as to catch the 90 new salamanders needed for my experiment.

We set out with the goal of catching 80 males and 10 females because my research will largely focus on male salamanders. This was my second foray into the world of salamander collecting, and so, I present to you the valuable knowledge I have gained  during these two expeditions.

 

 

1. During the summer months, pick the warmest day of a week where heavy rainfall occurred.

The Red Backed salamander borrows deep into the soil in the winter months and is virtually uncatchable at that time.

2. Find a conservation area you can easily access.

3.  STOP- Makes sure you have the proper permits!

In our case, three separate permits were required to catch and transport these salamanders out of Rockwood conservation area, Ontario.

4. Find a forested area away from campsites, beaches and roads.

Red Backed salamanders avoid humans and roads because of the disturbances they cause in the environment as well as the vibrations resulting from loud noises.

5.  Once in the forest, seek out areas where there is lots of tree cover protecting the soil from direct sunlight.

Salamanders are amphibians and although Plethodon cinereus does not spend any part of its life cycle in an aquatic environment, it still requires lots of humidity in order to survive. Moisture enables this lung-less and gill-less animal to breathe through its skin (cutaneous respiration) and is essential to maintaining internal balance.

6. In the shaded area, look under rocks, logs and leaf litter.

The Red Backed salamander is a nocturnal animal. It becomes active at night and only then will it come out and actively hunt its prey. Trouble is, at night they are much harder to see. You must therefore look for them in areas where they might be hiding, such as under rocks and logs.

You might catch a salamander having a light snack during the daytime, but, in this case, the prey is caught using an ambush predation strategy. This means that the salamander will simply sit and wait for the next potential meal to come along.

What do these salamanders eat, you might ask? Well, in the lab we feed them live crickets that we raise ourselves. We feed them young crickets because they are smaller than their adult counterparts and therefore more easily ingested. In the wild, however, they eat a variety of small arthropods.  This includes mites, insects and their larvae, and spiders. They will also eat slugs and earthworms. salamanders thrust their tongue out in a quick, forward motion in order to catch their prey.

7. Act quickly!

A startled Red Back will try to wiggle away or bury itself as soon as you lift the rock or the log that was covering it. We always miss a few because they are simply too fast for us.

8. Don’t grab them by their tails!

If you do this, you might find yourself with a wiggling salamander tail devoid of an actual salamander!

Salamanders have a nifty little predator avoidance strategy called “autotomy”.  They can autotomize their tails, a self-amputation act, when they feel threatened. Not only does this allow them to get away when a predator catches them by the tail, but, because the tail continues to jerk once it is discarded, this adaptation can also be used to distract a predator from attacking the arguably more important and meaty salamander body.

A salamander that survives a predatory attack will grow a new tail. This is called regeneration. Given enough time, the new tail will be just as long as the previous one, albeit slightly discoloured.

Red Backs have numerous predators. These range from small garter snakes to birds and shrews. However, under utopian conditions in which they would never encounter such threatening creatures, they can live up to 10 years.

9. Place them in a plastic bag with humid paper towels until you are ready to put them in a cooler with ice for transport.

Remember, humidity is important!

Otherwise you will end up with dried out dead salamanders.

10. Load the cooler into the car and bring them back to your lab where you place them individually in plastic containers such as these:

Salamander containers

In the end, we managed to trap 113 salamanders in 5 hours. We had had a lot more luck in May and, unfortunately, as we approach winter, these salamanders will be harder and harder to trap.

I was hoping to be able to sex all the salamanders on site, but the equipment we brought was not suitable for such a task. You see, in order to determine the sex of a salamander, one must have 2 very simple things: a very bright light and a humid plastic bag.

The salamander is placed in the plastic bag and immobilised using one’s fingertips. One must then hold the salamander up the to light to view the abdominal contents. A male will have testes on either side abdomen that show up as small dark elongated disks. A female will have no visible testes, but may be endowed with small eggs instead. This technique is called “candling” and is described in a journal article written by Gillette and Peterson, 2001.

We had brought a flashlight in order to sex the Red Backs but, given the outdoor lighting conditions, the flashlight’s rays were not sufficiently strong to pierce through the freshly caught critters. We decided to bring the salamanders back to the lab, where I spent the following three hours determining their sex. I identified 43 males, 57 females and 13 juveniles that were too young to sex accurately. We did not, in true Pokemon style, manage to “catch em’ all”.We will have to return to Rockwood next weekend to get some more males and return the excess females that I will not be using in my experiment.

Despite not reaching our goal, I enjoyed myself immensely in Rockwood. It felt good to work hard outdoors. This kind of activity also helps me remember that there is a tremendous amount of animal biomass right beneath our feet at any given time. In the city, one forgets much too easily that humans represent but a minuscule part of the biodiversity and biomass that can be found on Earth. The way we sometimes act shows just how removed we are from such realizations.

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A year ago today, I was in the process of approaching my current undergraduate thesis advisor in order to secure a spot in his herpetology/neurobiology lab. We had corresponded multiple times over the summer and I was setting up a meeting with him to discuss research ideas. I had decided that taking a thesis course was the right path for me because I wanted practical research experience.

I had to come up with an original scientific research project that I would work on over the course of the final year of my undergraduate degree. This is taken from the course outline:

 This two-semester course is intended to provide a deeper, more focused research experience than that provided in the project courses or in typical upper-level lecture courses

and is offered for students of excellent academic standing who possess a strong interest in pursuing postgraduate training in biological research.

My thesis advisor, who specializes in neurobiology, had previously been working on amphibians, which is the main reason I approached him.  You see, the first time I asked my parents for a snake was around the age of 5. As a toddler, animals of any type fascinated me but amphibians and, more specifically, reptiles, were my first true love. My parents undoubtedly hoped that I would grow out of my obsession for such “unsightly” creatures but, alas, that day never came. My mother thought them revolting, and my father, who is Trinidadian, thought it absurd to pay and care for an animal that is considered a pest in his country of origin. I kept asking them for the privilege of owning a scaly friend or two, but they never relented.

I must say that although they would never allow me to bring a reptile into the house, they did see my curiosity about the animal kingdom as something to be cultivated and encouraged. To their credit, they took me numerous times to zoos, pet shops and even the odd reptile farm. I’m sure they never imagined I would end up working in a herpetology laboratory, however.

With the help of my thesis advisor, I came up with a research idea and question that would explore how vision and olfaction interact in Red Backed salamander conspecific interactions. This means that I would try to find out how their sense of smell and their vision contribute to their interactions with each other under certain specific conditions that will be discussed in another post.

This blog will thus serve as a forum for me to share my experience as a fourth year student exploring the world of scientific research. More importantly, however, this blog is a vessel through which I hope to hone my writing skills in order to become a science journalist. I will therefore also report on interesting new scientific research as well as science topics that I hope you will find as exciting as I do.